root/ui/views/controls/webview/webview.cc

DEFINITIONS

1. allow_accelerators_
2. GetWebContents
3. SetWebContents
4. SetEmbedFullscreenWidgetMode
5. LoadInitialURL
6. SetFastResize
7. OnWebContentsFocused
8. SetPreferredSize
9. GetClassName
10. OnBoundsChanged
11. ViewHierarchyChanged
12. SkipDefaultKeyEventProcessing
13. IsFocusable
14. OnFocus
15. AboutToRequestFocusFromTabTraversal
16. GetAccessibleState
17. GetNativeViewAccessible
18. GetPreferredSize
19. WebContentsFocused
20. EmbedsFullscreenWidget
21. RenderViewHostChanged
22. DidShowFullscreenWidget
23. DidDestroyFullscreenWidget
24. DidToggleFullscreenModeForTab
25. AttachWebContents
26. DetachWebContents
27. ReattachForFullscreenChange
28. CreateWebContents

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/views/controls/webview/webview.h"

#include "content/public/browser/browser_accessibility_state.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/navigation_controller.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/render_widget_host_view.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/web_contents_view.h"
#include "ipc/ipc_message.h"
#include "ui/accessibility/ax_enums.h"
#include "ui/accessibility/ax_view_state.h"
#include "ui/events/event.h"
#include "ui/views/accessibility/native_view_accessibility.h"
#include "ui/views/controls/native/native_view_host.h"
#include "ui/views/focus/focus_manager.h"
#include "ui/views/views_delegate.h"

namespace views {

// static
const char WebView::kViewClassName[] = "WebView";

////////////////////////////////////////////////////////////////////////////////
// WebView, public:

WebView::WebView(content::BrowserContext* browser_context)
    : holder_(new NativeViewHost()),
      embed_fullscreen_widget_mode_enabled_(false),
      is_embedding_fullscreen_widget_(false),
      browser_context_(browser_context),
      allow_accelerators_(false) {
  AddChildView(holder_);  // Takes ownership of |holder_|.
  NativeViewAccessibility::RegisterWebView(this);
}

WebView::~WebView() {
  SetWebContents(NULL);  // Make sure all necessary tear-down takes place.
  NativeViewAccessibility::UnregisterWebView(this);
}

content::WebContents* WebView::GetWebContents() {
  if (!web_contents()) {
    wc_owner_.reset(CreateWebContents(browser_context_));
    wc_owner_->SetDelegate(this);
    SetWebContents(wc_owner_.get());
  }
  return web_contents();
}

void WebView::SetWebContents(content::WebContents* replacement) {
  if (replacement == web_contents())
    return;
  DetachWebContents();
  WebContentsObserver::Observe(replacement);
  // web_contents() now returns |replacement| from here onwards.
  if (wc_owner_ != replacement)
    wc_owner_.reset();
  if (embed_fullscreen_widget_mode_enabled_) {
    is_embedding_fullscreen_widget_ =
        web_contents() && web_contents()->GetFullscreenRenderWidgetHostView();
  } else {
    DCHECK(!is_embedding_fullscreen_widget_);
  }
  AttachWebContents();
}

void WebView::SetEmbedFullscreenWidgetMode(bool enable) {
  DCHECK(!web_contents())
      << "Cannot change mode while a WebContents is attached.";
  embed_fullscreen_widget_mode_enabled_ = enable;
}

void WebView::LoadInitialURL(const GURL& url) {
  GetWebContents()->GetController().LoadURL(
      url, content::Referrer(), content::PAGE_TRANSITION_AUTO_TOPLEVEL,
      std::string());
}

void WebView::SetFastResize(bool fast_resize) {
  holder_->set_fast_resize(fast_resize);
}

void WebView::OnWebContentsFocused(content::WebContents* web_contents) {
  FocusManager* focus_manager = GetFocusManager();
  if (focus_manager)
    focus_manager->SetFocusedView(this);
}

void WebView::SetPreferredSize(const gfx::Size& preferred_size) {
  preferred_size_ = preferred_size;
  PreferredSizeChanged();
}

////////////////////////////////////////////////////////////////////////////////
// WebView, View overrides:

const char* WebView::GetClassName() const {
  return kViewClassName;
}

void WebView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
  // In most cases, the holder is simply sized to fill this WebView's bounds.
  // Only WebContentses that are in fullscreen mode and being screen-captured
  // will engage the special layout/sizing behavior.
  gfx::Rect holder_bounds(bounds().size());
  if (!embed_fullscreen_widget_mode_enabled_ ||
      !web_contents() ||
      web_contents()->GetCapturerCount() == 0 ||
      web_contents()->GetPreferredSize().IsEmpty() ||
      !(is_embedding_fullscreen_widget_ ||
        (web_contents()->GetDelegate() &&
         web_contents()->GetDelegate()->
             IsFullscreenForTabOrPending(web_contents())))) {
    holder_->SetBoundsRect(holder_bounds);
    return;
  }

  // Size the holder to the capture video resolution and center it.  If this
  // WebView is not large enough to contain the holder at the preferred size,
  // scale down to fit (preserving aspect ratio).
  const gfx::Size capture_size = web_contents()->GetPreferredSize();
  if (capture_size.width() <= holder_bounds.width() &&
      capture_size.height() <= holder_bounds.height()) {
    // No scaling, just centering.
    holder_bounds.ClampToCenteredSize(capture_size);
  } else {
    // Scale down, preserving aspect ratio, and center.
    // TODO(miu): This is basically media::ComputeLetterboxRegion(), and it
    // looks like others have written this code elsewhere.  Let's considate
    // into a shared function ui/gfx/geometry or around there.
    const int64 x = static_cast<int64>(capture_size.width()) *
        holder_bounds.height();
    const int64 y = static_cast<int64>(capture_size.height()) *
        holder_bounds.width();
    if (y < x) {
      holder_bounds.ClampToCenteredSize(gfx::Size(
          holder_bounds.width(), static_cast<int>(y / capture_size.width())));
    } else {
      holder_bounds.ClampToCenteredSize(gfx::Size(
          static_cast<int>(x / capture_size.height()), holder_bounds.height()));
    }
  }

  holder_->SetBoundsRect(holder_bounds);
}

void WebView::ViewHierarchyChanged(
    const ViewHierarchyChangedDetails& details) {
  if (details.is_add)
    AttachWebContents();
}

bool WebView::SkipDefaultKeyEventProcessing(const ui::KeyEvent& event) {
  if (allow_accelerators_)
    return FocusManager::IsTabTraversalKeyEvent(event);

  // Don't look-up accelerators or tab-traversal if we are showing a non-crashed
  // TabContents.
  // We'll first give the page a chance to process the key events.  If it does
  // not process them, they'll be returned to us and we'll treat them as
  // accelerators then.
  return web_contents() && !web_contents()->IsCrashed();
}

bool WebView::IsFocusable() const {
  // We need to be focusable when our contents is not a view hierarchy, as
  // clicking on the contents needs to focus us.
  return !!web_contents();
}

void WebView::OnFocus() {
  if (!web_contents())
    return;
  if (is_embedding_fullscreen_widget_) {
    content::RenderWidgetHostView* const current_fs_view =
        web_contents()->GetFullscreenRenderWidgetHostView();
    if (current_fs_view)
      current_fs_view->Focus();
  } else {
    web_contents()->GetView()->Focus();
  }
}

void WebView::AboutToRequestFocusFromTabTraversal(bool reverse) {
  if (web_contents())
    web_contents()->FocusThroughTabTraversal(reverse);
}

void WebView::GetAccessibleState(ui::AXViewState* state) {
  state->role = ui::AX_ROLE_GROUP;
}

gfx::NativeViewAccessible WebView::GetNativeViewAccessible() {
  if (web_contents()) {
    content::RenderWidgetHostView* host_view =
        web_contents()->GetRenderWidgetHostView();
    if (host_view)
      return host_view->GetNativeViewAccessible();
  }
  return View::GetNativeViewAccessible();
}

gfx::Size WebView::GetPreferredSize() {
  if (preferred_size_ == gfx::Size())
    return View::GetPreferredSize();
  else
    return preferred_size_;
}

////////////////////////////////////////////////////////////////////////////////
// WebView, content::WebContentsDelegate implementation:

void WebView::WebContentsFocused(content::WebContents* web_contents) {
  DCHECK(wc_owner_.get());
  // The WebView is only the delegate of WebContentses it creates itself.
  OnWebContentsFocused(wc_owner_.get());
}

bool WebView::EmbedsFullscreenWidget() const {
  DCHECK(wc_owner_.get());
  return embed_fullscreen_widget_mode_enabled_;
}

////////////////////////////////////////////////////////////////////////////////
// WebView, content::WebContentsObserver implementation:

void WebView::RenderViewHostChanged(content::RenderViewHost* old_host,
                                    content::RenderViewHost* new_host) {
  FocusManager* const focus_manager = GetFocusManager();
  if (focus_manager && focus_manager->GetFocusedView() == this)
    OnFocus();
}

void WebView::DidShowFullscreenWidget(int routing_id) {
  if (embed_fullscreen_widget_mode_enabled_)
    ReattachForFullscreenChange(true);
}

void WebView::DidDestroyFullscreenWidget(int routing_id) {
  if (embed_fullscreen_widget_mode_enabled_)
    ReattachForFullscreenChange(false);
}

void WebView::DidToggleFullscreenModeForTab(bool entered_fullscreen) {
  if (embed_fullscreen_widget_mode_enabled_)
    ReattachForFullscreenChange(entered_fullscreen);
}

////////////////////////////////////////////////////////////////////////////////
// WebView, private:

void WebView::AttachWebContents() {
  // Prevents attachment if the WebView isn't already in a Widget, or it's
  // already attached.
  if (!GetWidget() || !web_contents())
    return;

  const gfx::NativeView view_to_attach = is_embedding_fullscreen_widget_ ?
      web_contents()->GetFullscreenRenderWidgetHostView()->GetNativeView() :
      web_contents()->GetView()->GetNativeView();
  OnBoundsChanged(bounds());
  if (holder_->native_view() == view_to_attach)
    return;
  holder_->Attach(view_to_attach);

  // The view will not be focused automatically when it is attached, so we need
  // to pass on focus to it if the FocusManager thinks the view is focused. Note
  // that not every Widget has a focus manager.
  FocusManager* const focus_manager = GetFocusManager();
  if (focus_manager && focus_manager->GetFocusedView() == this)
    OnFocus();

#if defined(OS_WIN)
  if (!is_embedding_fullscreen_widget_) {
    web_contents()->SetParentNativeViewAccessible(
        parent()->GetNativeViewAccessible());
  }
#endif
}

void WebView::DetachWebContents() {
  if (web_contents()) {
    holder_->Detach();
#if defined(OS_WIN)
    if (!is_embedding_fullscreen_widget_)
      web_contents()->SetParentNativeViewAccessible(NULL);
#endif
  }
}

void WebView::ReattachForFullscreenChange(bool enter_fullscreen) {
  DCHECK(embed_fullscreen_widget_mode_enabled_);
  const bool web_contents_has_separate_fs_widget =
      web_contents() && web_contents()->GetFullscreenRenderWidgetHostView();
  if (is_embedding_fullscreen_widget_ || web_contents_has_separate_fs_widget) {
    // Shutting down or starting up the embedding of the separate fullscreen
    // widget.  Need to detach and re-attach to a different native view.
    DetachWebContents();
    is_embedding_fullscreen_widget_ =
        enter_fullscreen && web_contents_has_separate_fs_widget;
    AttachWebContents();
  } else {
    // Entering or exiting "non-Flash" fullscreen mode, where the native view is
    // the same.  So, do not change attachment.
    OnBoundsChanged(bounds());
  }
}

content::WebContents* WebView::CreateWebContents(
      content::BrowserContext* browser_context) {
  content::WebContents* contents = NULL;
  if (ViewsDelegate::views_delegate) {
    contents = ViewsDelegate::views_delegate->CreateWebContents(
        browser_context, NULL);
  }

  if (!contents) {
    content::WebContents::CreateParams create_params(
        browser_context, NULL);
    return content::WebContents::Create(create_params);
  }

  return contents;
}

}  // namespace views